This chapter describes studies focusing on aporphine alkaloids. Neolitsine is the first aporphine found to possess two methylenedioxy groups. It is present in Neolitsea pulchella Alerrill, from which it was isolated as crystals melting at 149°–150°, and analyzing for C19H17NO4. The alkaloid gave a positive Labat test, and formed a picrate, a methiodide that crystallized with 1 mole of methanol, and a hydrochloride that charred at 219°C. From the bark and wood of Lccurzcs nobilis L. the new noraporphine launobine was obtained, C18H17O4N. The alkaloid has one methylenedioxy, one methoxyl, and one hydroxyl. Clarke–Eschweiler N-methylation was found to give (+)-bulbocapnine. Mecambroline was isolated from Meconopsis cainbrica Vig. (Papaveraceae), and the elemental data indicated the value C18H17O3N. Color tests showed the presence of a methylenedioxy and a phenolic group. Mecambroline was also obtained in 71% yield by refluxing the proaporphine alkaloid mecambrine in dilute hydrochloric acid. Two alkaloids have been obtained from the leaves of Ocotea glaziovii Mez (Lauraceae), both of which analyzed for C18H19NO3. One was named “glaziovine” and shown to possess the proaporphine structure as illustrated in the chapter. The other alkaloid was identified as 1,10-dihydroxy-2-methoxyaporphine. © 1967, Academic Press Inc.